The present invention relates to a control lever equipment for operating a brake or a clutch in a vehicle having a steering bar handle at the front thereof, for example, in a motor bicycle, a motor tricycle and a three or four-wheeled bogie.
A conventional control lever equipment for operating a brake or a clutch of a bar handle vehicle such as of a motor bicycle is provided with a control lever composed essentially of two pieces, i.e., a lever piece to be gripped and operated by a rider and an operating piece for operating a hydraulic master cylinder or a wire by gripping the lever piece; and a grip allowance adjusting mechanism interposed between the lever piece and the operating piece. An example of such equipment is disclosed in Japanese Unexamined Utility Model Publication (KOKOKU) No. 7-17667.
The grip allowance adjusting mechanism disclosed in the above publication contains an adjusting pin fitted pivotally in a supporting hole defined through the operating piece, a plurality of cam faces formed contiguously on the circumference of the shaft of the pin so that they are located at different distances from the axis of the adjusting pin respectively and an abutting face formed either on the operating piece or on the lever piece. The cam abutting face is abutted selectively against one of the cam faces to achieve widening and narrowing of the grip allowance between a grip attached to one end of a handle bar and the lever piece depending on the constitution and preference of the rider. The adjusting pin has the same number of recesses as the cam faces formed on the shaft end face intermittently along the periphery. A coil spring is located in an adjusting pin fitting hole of the operating piece, and a ball urged resiliently by the coil spring is engaged resiliently with a selected one of these recesses.
However, since the coil spring is attached to the adjusting pin to be offset from the axis thereof, the resilience of the coil spring acts as an offset load upon the adjusting pin to tilt it with respect to the central axis of the adjusting pin fitting hole. Thus, vibration during driving can cause backlash of the adjusting pin. Meanwhile, when the grip allowance is to be changed, the adjusting pin cannot be pivoted smoothly, and the adjusting pin is worn or damaged by interference with the lever piece and the operating piece, shortening the life of the control lever equipment.
It is an objective of the present invention to provide a control lever equipment for a bar handle vehicle, which enables smooth pivoting of the adjusting pin in adjusting a grip allowance, while preventing backlash of the adjusting pin fitted in the adjusting pin fitting hole.
The control lever equipment for a bar handle vehicle according to the present invention contains a support shaft attached to a holder fixed to a handle bar, a control lever pivotally supported by the support shaft and a grip allowance adjusting mechanism for widening and narrowing a grip allowance to be secured between the control lever and a grip of the handle bar. The control lever is composed essentially of the two pieces, i.e., a lever piece and an operating piece which pivot coaxially on the support shaft independent of each other. The grip allowance adjusting mechanism contains an adjusting pin attached either to the lever piece or to the operating piece pivotally on an axis parallel to the support shaft; a plurality of cam faces formed contiguously on the circumference of the shaft of the adjusting pin so as to locate at different distances from the axis of the adjusting pin respectively; and a cam abutting face formed either on the operating piece or on the lever piece. The cam abutting face is urged to be selectively brought into abutment with one of the cam faces by pivoting the adjusting pin. A resilient piece is interposed between the adjusting pin and a bearing for journalling the shaft end of the adjusting pin, formed either on the lever piece or on the operating piece, to be coaxial with the adjusting pin. The adjusting pin is engaged under the resilience of the resilient piece either by the lever piece or by the operating piece.
A typical example of the resilient piece is a coil spring disposed around the axis. The bearing is a recess, and the bottom of the bearing serves as a seat for the resilient piece.
Another typical example of the resilient piece is a leaf spring disposed around the axis. Further, the adjusting pin has a circumferential groove formed on the shaft thereof, which is to be engaged with the leaf spring.
According to the control lever equipment for a bar handle vehicle according to the present invention, since the resilience of the resilient piece acts axially upon the adjusting pin, the pin can be retained without tilting. As a result, the adjusting pin can be pivoted smoothly, and the grip allowance can be changed easily. In addition, no interference occurs between the adjusting pin and the control lever to cause either damage or wearing of them which are observed in the conventional equipment. Besides, no unnecessary load is applied to the components of the grip allowance adjusting mechanism, so that durability of the control lever equipment can be enhanced.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings which illustrate by way of examples the principles of the invention.